Train services between Edinburgh and Cowdenbeath have been suspended while Glasgow Central/Kilmarnock/Stranraer services are to terminate and start back from Ayr.
Services between Inverness and Aberdeen will be delayed or revised.
Rail services between Edinburgh and Arbroath will be terminated at and started back from Dundee with Montrose and Inverurie routes suspended.
Scot Rail has also cancelled services and warned passengers of delays after the operator was forced to slow down trains because of the weather.
It cancelled Tuesday’s services between Stranraer and Girvan.
London North Eastern Railway also announced a series of delays and alterations because of the weather.
Elsewhere, a tree blocking the railway between Carstairs and Lockerbie has resulted in the closure of the line.
A Transport Scotland spokesman said: “The conditions brought in by Storm Barra continue to have the potential to impact the trunk road network, as well other modes of transport.
“As always, we urge people to check the latest information before they set off, drive to the conditions and follow Police Scotland travel advice.”
Storm Barra, the second winter storm of the season, will continue to batter the UK tonight, with yellow warnings in Scotland set to end at midnight.
Parts of Scotland are on alert as high winds and snow start to batter the country as Storm Barra sweeps across the UK.
The storm has already brought snow, with people in South Lanarkshire seen clearing their driveways, and high winds have caused disruption on roads as they bring down trees.
The Met Office has issued yellow weather warnings for snow and wind, with forecasters warning of gusts of up to 80mph on the west coast and of up to 65mph around the east coast.
Gusts in Scotland have reached as high as 68mph, the Met Office has said, as Storm Barra makes its way across the country, with forecasts predicting more extreme weather later this evening.
The gust was recorded in Machrihanish, near Campbeltown in Argyll, on Tuesday afternoon, with strong winds forecast to continue throughout the night.
“The strong winds will continue across the UK this evening, bringing widely 40-50mph, and up to 65mph at the coast. This could give tricky travelling conditions, some power outages and large waves at the coast,” said Becky Mitchell, senior operational meteorologist at the Met Office.
“Rain and snow will clear Scotland after midnight and the winds will gradually ease for most of the country.
“However, it will stay windy in parts of south-west England and Wales, where a yellow wind warning remains in force through Wednesday.”
Rod Dennis, RAC Breakdown spokesman, urged people to drive to the road conditions.
“As Storm Barra batters Britain, drivers need to really have their wits about them to stay safe. We urge drivers to stick to major routes wherever possible, slow down to the right speed for the conditions and take particular care when passing high-sided vehicles to avoid being buffeted off course,” he said.